Circuit interrupting device



Feb. 10, 1942, L. R. LUDWIG ET AL CIRCUIT INTERRUPTING DEVICE 7Sheets-Sheet 1 Filed Sept. 19, 1939 Feb. 10, 1942. 1.. R. LUDWIG ET ALCIRCUIT INTERRUPTING DEVICE Sheet 2 Filed Sept. 19, 1959 7 Sheets- 47INVENT QRS Leon RLUdH/I'g; James/1. in? 25 and Feb, 10; 1942.v L. R.LUDWIG ET AL CIRCUIT INTERRUPTING DEVICE 7 Sheets-Sheet 5 Filed Sept.19, 1959 7 Sheets-Sheet '7 Frakes. and

fie/d, Admin/s frail/x r/ha M. 56/10 5 fan/ Feb. 10, 1942.. L. R. LUDWIGETAL CIRCUIT INTERRUPTING DEVICE Filed Sept. 19, 1939 w w M 2 7 a H M w3 M i..- mw n F 3 7 5 5 l w a a 5 9 5 M 2 3 u a w n m m n 900 Ltd/y,James HINVENTORS Patented Feb. 10, 1942:

cmcmr r'u'raanur'rmc DEVICE Wilkinsburg, and James H.

Leon R. Ludwig,

Frakes, Edgewood, and Stanley T. Schofleld,

deceased. late of Wilkinsburg, Pa., by Martha M. Schofleld,administratrix, Wllkinsburg,

assignors to Westinghouse Electric at Manu- East Pittsburgh, Pa., a

facturing Company, corporation o! Penney lvania Application September19, 1939, Serial No. 295,590

' (or. Edit-48) 57 Claims.

This invention relates to circuit interrupting devices and moreparticularly to disconnecting -switches capable of interrupting loadcurrents.

In the transmission of electrical power, the disconnecting switch.heretofore has been used mainly to isolate sections of a transmissionline from each other or for isolating a load circuit from its associatednetwork. The switching operation inmostsuch instances necessarily had tobe made under conditions of no-load on the circuit being disconnected.Even under conditions of no connected load, the high voltages'now prevalent in transmission practice produce charging currents of appreciablemagnitude. Attempts have been made to interrupt line charging currentsand light load currents with disconnecting switches equipped with arcinghorns. Although certain switches, particularly oi the low-voltage type,have successfully interrupted charging and small load currents, theiruse for this purpose is unsatisfactory since the exposed are drawnduring the circuit opening operation may be blown across the line or togrounded parts thus causing the flow of fault currents.

The main object of our invention is to pro= vide a disconnecting switchcapable of interrupting load and charging currents oi a trans missionline without the external display oi an:

Another object of our invention is to provide a circuit interruptingdevice capable of inter rupting load currents and having a form suitablefor movement as a whole into and out of on gagement with at least insertan appropriate air ing circuit interruption.

A further object oi the invention is to provide a load breakdisconnecting switch wherein a movable blade means for establishing anair break in the circuit completely encloses separable contacts whichare actuated to the open circuit position in response to the initialmovement of the blade means to the disconnect position.

A more specific object of the invention is to provide a load breakdisconnecting switch'having separable contacts and an arc extinguishingstructure enclosed in a movable blade structure wherein the contacts areactuated to the open circuit position prior to structure out of theconnected circuit.

Still another object of the invention is to provide operatingmeans for aload break disconnecting switch of the aforesaid type which sequentiallycauses the contacts to separateat a speed independently of the speed atwhich the gap in the circuit follow= movement of the blade one lineterminal so as to operating means is moved and then moves the bladestructure to the disconnect position.

A further objec" or the invention is to provide a circuit protectividevice embodying two serially related circuit interrupting unitscapable, respectively, of interrupting load and overload currents. andat least one 01 which is movable out of the circuit for inserting adisconnect gap therein.

It is also an object oi our invention to provide a novel circuitinterrupting unit of the enclosed type suitable for operation withdisconnect switches oi conventional form for converting such switches toload brealr devices.

Qther objects and advantages will appear more fully in the followingdescription, when taken in connection with the accompanying drawings, inwhich: i

Figure l is a side view of a load break disconnectihg' switch of ourinvention showing the movable blade means in longitudinal section;

Fig. 2 is a iront view partially in section of the switch shown in Fig.i;

Fig. 3 is side view showing the switch oi Fig. i in the open circuitposition;

his. 4 is side view partially in section of a hoolr StiCliZ operatedindoor type load break dis== connecting switch embodying our invention;

Fig. 5 is a fragmentary view partially in section of the upper end ofthe blade member of the switch shown in Fig. a and is taken at rightangles to the position illustrated in that figure;

Fig. 6 is a side view illustrating the circuit interrupter of ourinvention when used in conjunction with an overload protective devicesuch as fuse;

Fig. 7 is a side view showing another form of load break disconnectingswitch embodying our invention;

Fig. 8 is an enlarged sectional view of the circuit interrupting unit ofthe switch shown in Fig. '7 showing the contacts of the interruptingunit in the closed circuit position;

Fig. 9 illustrates the relative position or the various parts of theinterrupting unit of Fig. 8 when that unit is in the open circuitposition;

Fig. 10 is an enlarged sectional view of a modiflied form of circuitinterrupting'unlt as may be employed in the switch structure shown inFig. l; and

Fig. ii is a sectional view of the unit of Fig. 10, showing theopen-circuit position.

Referring to Figs. 1,2 and 3 oi! the drawings, the reference number Itdesignates a base which carries insulators l5, l1 and I9 disposed inspaced relation with respect to each other, as shown. The free ends ofthe insulators l1 and H are joined by a conducting support member 2|.The support member 2| carries a pair of spaced brackets 23 having across shaft 25 extending therebetween adjacent their outer ends.Journalled for pivotal movement on the shaft 25 is a casing 21 ofconducting material which carries a hollow blade member generallyindicated at 29. The blade member 29 comprises a tubular member 3| ofinsulating material screw threaded onto a metallic sleeve 33. The sleeve33 extends through a suitable aperture into thecasing 21 and has athreaded collar 35 which secures per-- tions of the upper wall of thecasing against the tubular member 3|.

A tubular conducting member W is concern trically disposed within theinsulating member 3i and makes contacting engagement at its lower endwith the tubular member 33. The upper end of the member 31 has a flangedportion 39 which serves as one of the contacts within the tubular blademember M. A sleeve of insulating material 4| surrounds thetubularconducting member ll so as to provide an annular arc passage 43,the outer wall of which is defined by the tubular insulating member at.".lThe lower end of the arc passage 43 is closed by an annular member B5oi insulating material abutting the conducting sleeve 33. .Secured tothe upper end of the insulating tube 31 is a tubular cap member All ofconducting material. Surrounding the cap mem ber 41 is a comicallyshaped sleeve t9 also of corn ducting material which projects downwardlyso as to overlap the upper end portion oi the insulating member 3 lsleeve id carries at least two inwardly projecting diametrically-opposedcontact segments 5i, (Fig. 2) which project through suit able aperturesformed in the members ill and ti. Normally disposed between the contactsegments 5! and the contact portion 39 is a movable contact ring 53carried by the lower end oi? a mov able tubular barrier member 55 ofinsulating material. The barrier member 55 is closed at its upper end bythe member bl to which is secured an operating rod 59 having slidingmovement through the tubular conducting member ill. The lower end of theoperating rod 59 has secured thereto a disc 6|. A compression spring 63,one end of which bears against the upper end of the metallic sleeve 33and the other end against the disc 8|, biases the operating rod 59downwardly so as to move the barrier member 55 and its associatedcontact 53 into the arc passage ill. The contact 39 and the contactsegments bl are provided with grooves tit and B3 so as to confinearcing," to the lower portions thereoi thereby preserving the upperportions against the erosive efiects of the arc. Movement of theoperating rod 59 is normally prevented by means of a latch pivotally'carried by the sleeve 35. The

till

tilt

method of releasing the latch 65 for the purpose of separating thecontacts within the blade member 29 will appear more fully hereinafter.

The insulator l5 carries a terminal member 5'! having two outwardlyextending supports 69 thereon. Pivoted to the supports 53 and havinglimited swinging movement therewith are a pair of arms H. The free endsof the arms ll support a U-shaped contact yoke 13 which is also mountedfor limited pivotal movement with respect to the arms. The contact yoke13 has an inner contact receiving surface which tapers in- 75.

wardly in the upward direction and is adapted to receive the conicalsleeve portion 49 of the blade member 29. A spring '15 tends to causearms H to rotate in a counter-clockwise dlrection as viewed in Figs. 1and 3, about their pivotal supports. The spring 11 in a similar mannerbiases the contact yoke 13 for clockwise rotation about its pivotalsupport at the ends of the arms H. The purpose of this particularconstruction will appear more fully hereinafter.

When the blade member 29 is in the position shown in Fig. 1, the conicalsleeve 49 is tightly wedged into the contact yoke 13 so that the contactsegments 5i exert a high pressure against the moving contact 53 which,in turn, malzes high pressure contact with the fixed contact portionFlexibility within the conical sleeve 49 is attained by slotting theleft hand side thereof, as more clearly shown at "ill in Fig. 1. Thecontact ring 63 is also preferably slotted to impart ilexlbility theretoand thereby permit the abovementioned high pressure contact action. Thusthe circuit through the interrupter proceeds from the terminal 551,shunt Bl to the contact yoke 13, contacts ill, 53, 3t, conducting memberill, conducting sleeve till, casing ill, shunt support 2|, and finallyterminates with a line terminal B3 secured to the support member ill.

In order to operate the blade member it to the open and closed position,the insulator i5 is mounted ior rotativc movement with respect to thebase ill and is journaled at its free end in the conducting supportplate ill. lilecured to the outer end of the insulator ill "is anoperating arm oil having an operating linlii ll'l coupled thereto, by auniversal joi The other end of the operating link 8"! is pivotallycoupled in a like manner to a boss Ill secured to the side oi the casingas more clearly shown in Fig. it. it will thus be seen that since thecasing is pivotally mounted upon the cross shai't iii, rotation ofinsulator ill in the clockwise direction, as viewed in it, will causethe link. 8'! to rotate the casing ill about the cross shaft 25 and in aclocltwise direction to the peeltion shown in Fig. 3. The cross shaft itis ilxedly secured to the brackets it so as to prevent rotation thereoiwith respect to the bracltets. Fixedly secured to the cross shaft illand disposed in a hm-mental direction, as shown in li ies. l and 3,

is an actuating arm ill. lfloupled to the free end of the arm Si is anactuating llnlr the other end oil" which is pivotally connected to theintermediate portion oi an operating lever The operating lever ispivoted at ill to the casing Ti and has its free end provided with anabutment 9!).

From the relation of the parts shown in Fig. i, it will be observed thatas the casing ill and the tube 25 begin to rotate in a cloclrwisedirection, the latch lit through. pivoted trigger member llll engagesthe operating arm Si, thus rotating the latch 65 in a clockwisedirection to release the disc 6i, thereby permitting the spring 63 toactuate the operating rod 59 downwardly carrying with it the movablecontact ring 53 and the insulating barrier 55. An arc will be drawn inthe arc passage 43 which is confined to the narrow clearances betweenthe three concentric tubes 3!, 55 and 4|. Although contact 53 issubjected to relatively high lateral pressure when engaged, spring 63 isstrong enough to cause longitudinal sliding of contact 53 when latch 55is released. The concentric tubular members 3|, 4! and 55 are preferablyconstructed of insulating material which evolves considerable gas whenacted upon by an arc to aid in extinguishing the are, for example, hardfiber has been found a suitable material for this purpose. As thebarriermember 55 moves into the annular arc passage til, the arc gases aredriven through the arc stream and ment a blade membergenerallycindicated at I ll. The blade member II I comprises a tubularmember H3 of insulating material secured at its lowmust escape to thespace provided within the enclosed cap member ill. This metallic capmember ll serves as a condenser for the arc gases escaping from thespace between the barrier '55 and the tubular member 33. Inasmuch as theoperating rod til permits some gas to escape therealong through thetubular conductor 3'5 into the casing 27, the latter also serves as acompletely enclosed condensing chamber.

Tripping of the latch @355 causes the contacts to open within the blademember 293 at a high speed which is independent of the speed of movementoi the actuating insulator B9. In ia'ct, the contacts within the blademember 2d are moved to the open circuit position and the arc is extinguished prior to separation of the conical sleeve it from the contactyoke Contact between blade member 29 and the yoke it continues dur ingthe initial opening movement of the blade member is by virtue of thepivotal linkage ll supporting the contact yoke it. Thus the yoke er endto a metallic ferrule Ill. The ferrule ill has a metallic sleeve H9extending upwardly into the insulating tube lit and is joined with a me?tallic collar i211 which, in turn, supports a tubular conducting memberM3, the upper end of i which has a contact portion 62b. The tubular illconducting member B23 is surrounded by a tubular sleeve lZll ofinsulating material so asto form an annular arc passage 629 similar tothe are passage 83 previously, described in connection with Figs. 1 to ait remains in contact with the sleeve 39 until the yoke reachestheposition shown in Fi 3.

It will thus be seen that the circuit is completely a interrupted withinthe blade member is prior to disengagement oi the member from thecontact yoke When the operating rod 59 reaches its full open position,it bears against the abutment 99 of the operating lever 95. As the blademember is rotated to the open circuit position, the connecting link t3causes the operating lever to move the operating rod 59 inwardly withrespect to the blade 29 until the disc til is again engaged by the llatch. 55, thereby relatching the-contacts within the blade member inthe closed circuit position at such time when the blade member reachesits iull= open position, as shown more clearly in Fig. 3. As the blademember 2% is again brought to the closed circuit position by rotation ofthe insulator it in the counter-clockwise direction, as viewed in Fig.2, the conical sleeve 59 engages the contact yoke l'ii while the latteris in the position shown in Fig. 3.

It will be apparent that continued rotation of the blade 29 in acounter-clockwise direction, as viewed in. either Fig. l or 3, willcause movement of the yoke l3 downwardly with respect to the sleeve 49,thereby securing a high pressure wiping contact which also exerts a highpressure on the inner contacts 5!, 53 and 351?. As the blade member 29moves into its final closed circuit povsition, the latch 65 clears theactuating arm 9i because the trigger member IN .is pivotally mountedupon the latch 65 for rotative movement in the counter-clockwisedirection and is biased for rotation in the clockwise direction againsta suitable stop, as shown in Fig. l. The

conductor A rnetallic closure cap i3i closes the end of the tube lit.Surrounding the lower end'of cap 935 and also overlapping the end of.the in sulating tube M3 is a metallic sleeve member having a pair ofblade members till, only one oil which is shown, adapted to engage oppossides of a single blade terminal carried by the insulator M95. The cap630 has an con" tact portion E39 disposed at the lower end there ofopposite the contact portion oi the tubular an annular movable contactEdi is normally positioned in bridging relation with respect to thecontacts 1125 and ried by the lower end of a movable barrier her 1630finsulating material. The upper end of the barrier t lt is closed by athreaded plug i l-5 to which is secured the upper end of an operatingrod t ll.

The operating rod Ml extends downwardly through the tubular conductorand is provided at its lower end with a disc Mil. Disposed between thedisc its and the tubular conductor is a spring 55H for moving thecontact Edi and the barrier M3 into the arc, chamber The contact H lland the barrier M3 are normally held against movement by the spring Hitby a movable latch member Q53 engaging a latch pin extendingtransversely of the cap member When the switch is in the position shownin Fig. 4, the circuit thereto proceeds through the terminal member Hi,the blade 11 sleeve lilfi, cap member 53H, contacts 839, Nil, Nil,tubular conductor i253, collar lZl, sleeve Mil, ferrule ill to the lowerterminal member lbs. The blade member ill is held in the closed circuitposition against accidental opening by heavy currents flowingtherethrough by means of a latch lever 15?, pivoted to the closure capHill at lfiil. The left hand end of the latch lever lEil engages a catchit! forming an upward extension of the terminal 931. The latch leverital has two branches extending oneon each side of the closure cap I35which unite on thegright hand side thereof and terminate in a loop I63,which serves as a-means for engaging the customary hook stick ,foroperating the blade member ill to open and closed circuit positions. Thelatching lever I5! is also pivotally connected by a pair of upstandinglinks I65 to a transversely extending. release bar Nil. The release baris adapted to slidably operate. in slots I69 provided 'on diametricallyopposite sides of the cap IM I6I and also actuates the links I55downwardly causing the release bar I61 to engage the upper cam surfaceI13 of the latch I53, forcing the latch I53 to the left, out ofengagement with the bar I55, thereby releasing the operating rod I41,whereupon the spring II actuates the movable contact HI and the barrierI43 downwardly into the arc chamber I29. The are thus drawn in theconfined annular spaces on either side of the barrier member I43 isquickly extinguished in the manner previously described in connectionwith the structures shown in Figs. 1 to 3.

Upon the release of the moving contact memher I by the downward movementof the loop I93 and also the simultaneous release of the latch lever I51from the catch IBI, it is apparent that an outward movement of the loopI63 will cause the blade member III to be rocked about its lower pivotalsupport to the open circuit position. In the open circuit posi tion thedisc I49 secured to the lower end of the operating rod I41 rests againsta similar disc I15 secured to the upper end of a rod I11 extendingthrough the lower end of the ferrule H1. The lower end of the rod I11 isconnected by a link I19 to a fixed bracket arm I8I mounted upon thecontact terminal I09 carried by the insulator I01. The bracket I8I, thelinkage I19 and the rod I11 are so arranged with respect to the blademember III that upon movement of the latter to the full open circuitposition, the rod I11 is moved inwardly with respect to the blade memberIII to cause the operating rod I41 to be moved to the closed circuitposition so that the pivotal latch I53 again is forced to engage the barI55, thus reseating the contacts within the blade member III for asubsequent circuit opening operation.

In Fig. 6 we have shown a circuit interrupting structure embodying theprinciples heretofore described in .conjunction with an overloadprotective device which also serves to function as a circuit disconnect.In Fig. 6, a base I83 carries three insulators I85, I81 and I89. Mountedupon the insulator I85 is a line terminal member I9I having a contactclip I93 which engages the upper end of a fuse I95 which may be of thetype shown in H. L. Rawlins Patent No. 1,976,634, issued October 9,1934. The fuse I95 is pivotally mounted at its lower end to a bracketextension I91 carried by a terminal I99 supported upon the insulatorI81. The terminal I99 also has a yoke-like member 20I embracingthe'upper end of a circuit interrupting unit 203; The lower end of theinterrupting unit 203 is secured to, and supported by, a conductingterminal 205 carried by the insulator I89. It will be noted that theinterrupting unit 203 in this instance is similar in construction to theblade member III shown in Fig. 4, except that the operating rod 201,which corresponds to the rod I41 in Fig. 4, is provided with a rollertype catch 209 which is adapted to engage a latching lever 2I I, whichis pivoted at its upper end to the side of the ferrule 2I3 of theinterrupting unit 203. The operating rod 201 also has a lower extensionwhich terminates in a loop 2I5 for the insertion of a hook stick torender the rod manually operable.

The circuit through the protective device, as shown in Fig. 6, proceedsfrom the terminal I9I through the fuse tube I95, the bracket I91,terminal I99, interrupting unit 203, to the terminal 205. To interruptthe circuit while carrying normal load currents, it is necessary toactuate the latch lever 2 to release the operating rod 201. This isaccomplished by a lever 2I1 pivoted at 2I9 to a bracket 22I secured tothe base I83. The right-hand end of lever 2I1 has a roller 223 normallyengaging the lower side of the latch lever 2II. The left hand end of thelever 2I1 has an offset portion 225 adapted to be engaged by a roller221 journalled in an actuating lever 229 which is also pivotally mountedat 23I to the bracket 22I. The actuating lever 229 is provided with anoperating ring or loop 233 into which a hook stick may be inserted formoving the lever 229 downwardly, thus rocking the lever 2I1 in thecounterclockwise direction, causing the roller 223 to engage the latchlever 2I I, raising the same to release the roller 209 and thus permitthe operating rod 201 to be moved to the open circuit position. Closingof the contacts within the circuit interrupter 203 is accomplished byinserting a hook stick in the loop 2I5 and forcing the rod upwardlyuntil the latch 2II again engages the roller 209.

When the circuit through the interrupter 203 has been opened in themanner described, the fuse tube I95 may be swung about its lower pivotalsupport by the insertion of a hook stick in its operating ring 235 inthe usual manner. In the event that an overload occurs in the circuit,the fuse I95 blows and interrupts the circuit, thereby also providingoverload protection. It is thus seen that by this simple arrangement ofmounting the fuse structure I95 and the circuit interrupting device 203upon three insulators, one of which serves as a common support for thetwo interrupting units, economy in mounting structure is obtained and aprotective device is provided which serves to interrupt the circuit onboth load and overload currents. In addition, means are provided forplacing an appreciable air gap in the circuit for isolating the loadcircuit from the transmission line without providing for movablymounting the load break device.

In Fig. "I a circuit interrupting unit embodying the ieatures of ourinvention is shown applied to a more or less conventional disconnectswitch. The disconnect switch shown in Fig. '1 is fully shown anddescribed in H. J. Crabbs Patent No. 2,067,659, issued January 12, 1937,and assigned to the assignee of the instant application. As set forth inthe above-named patout, the disconnect switch proper comprises a base Iupon which are mounted three spaced insulators 243, 245 and 241. Theinsulators 245 and 241 are joined by a conducting support plate 249, towhich one terminal of the switch is connected. The insulator 245 alsocarries a pair of upstanding brackets 25I, only one of which is shownand to whichis pivotally mounted for swinging movement a blade member253. A second blade member 255, joined near its outer end to the blademember 253 by a pair of links 251, is connected at its other end to alink 259, which, in turn, joins the pivotal axis of the blade 253. Theinsulator 241 is mounted for rotative movement and has an actuating arm26I secured thereto which is universally connected by means of anoperating link 283 to the pivotal connection of blade 255 and arm 259.The free ends of the blades 253 and 255 are adapted to be engaged by aU-shaped conprior to the introduction of an air gap in the circuit,which contacts are completely enclosed tions.

also serves as a condenser for condensing the portion m of the latch mengages the cam surface 333 at the lower end of the slot 332 so as toforce the latch m to the left after the movable contact 293 has beenbrought in registration with the contacts 233 and 293. The contactstructure, therefore, is again in the closed circuit position inreadiness for a subsequent opening operation.

Fig. 10 illustrates another form of circuit interrupting unit which issimilar to the unit shown in Fig. 8, except that the support rod 333 hasbeen replaced by a support rod 321 of uniform cross section. Surroundingthe support rod 321i is a tubular operating member 329, theupper end ofwhich makes a swivel connection at 33l with the upper end of the movablebarrier member 29!. The operating member 329 is also provided with apair of diametrically opposed helical slots 333 into which the oppositeends of a guide pin as extend. The guide pin :35 is held fixed withrespect to the support rod 321 and is mounted at the upper end thereofby a screw 331. The lower end of the operating member 329 has aninwardly extending flange 339 for engaging one end of a compressionspring 341 surrounding the rod 321. The other end of the spring 3presses against the support for the guide pin 335. It will thus be seenthat the spring 3 tends to urge the operating member 323 downwardlycarrying with it the barrier member 295 and the moving contact 293.

Movement of the operating member 329 is prevented by a bayonet latch 343secured to the upper end of the operating member 329 which engages twoinwardly extending spring pressed catch members 345. Thus when theinterrupting unit is moved as a whole during the switch openingoperation as previously described with respect to the support rod 321,and against the compression of spring 341, the operating member 329 willbe rotated about its longitudinal axis with respect to the catch members345. The pitch of the helical slots 333 is so chosen that the operatingmember 329 and the bayonet latch 343 will have rotated substantially 90when compression oi the spring 3 is complete. When the bayonet latch 343has rotated 90 from the position shown in Fig. 10, it will be releasedfrom the catch members 345, thus permitting the barrier member 295 tomove the movable contact 293' out of engagement with the contacts 283and 239 to the position shown in Fig. 11. The are thus drawn in the arcchamber 219 is quickly extinguished in the manner previously described.

Resetting of the contacts to the closed position during the closingstroke of the switch is similar to that described in connection withFigs. 8 and 9 except that the movement of the interrupting unit in thisinstance towards the support bracket 21! causes the bayonet latch member343 to be forced between the catch members 345, which are spring pressedand spread to permit the enlarged portion of the latch member to passtherethrough. The catch members thereafter spring back in place torelatch the contacts in the closed circuit position.

It will be noted that the circuit interrupting units described in Figs.8 through 11 embody a contact structure for interrupting the circuit andprotected from exposure to climatic condi- The metallic cap or closuremember 285 generated gas during the circuit opening operation, andprevents the existence of external arc or flame.

Although we have shown and described several specific embodiments'of ourinvention, it is to be understood that the sam were for the purpose ofillustration and that changes and modiflcations may be made by thoseskilled in the art without departing from th spirit and scope oi theappended claims.

W claim as our invention:

1. In a circuit interrupter, a pair of concentric tubes of insulatingmaterial defining an annular arc passage, separable contact means fordrawing an are adjacent one end of said are passage, and a third tube ofinsulating material relatively movable between said pair of concentrictubes for causing said are to be restricted in cross section andlengthened along a path substantially twice the length of the relativemovement between said last-named tube and said pair of concentric tubes.

2. In a circuit interrupter, a pair of concentric tubes of insulatingmaterial defining an annular arc passage, separable contact means fordrawing an arc adjacent-one end of said are passage,

- and a third tube of insulating material normally disposed outside saidarc passage and biased for movement into said are passage upon formationof an are between said separable contacts, said third tube of insulatingmaterial being dimensioned to substantially fill said arc passage" whenmoved therein for confining the arc to the restricted clearances betweensaid tubes.

3. In a circuit interrupter, a. pair of concentric tubes of insulatingmaterial defining an annular arc passage, a pair of stationary contactsdisposed adjacent one end of said pair of concentric tubes, a bridgingcontact normally coacting with said pair of stationary contacts tocomplete the electric circuit therebetween, means for moving saidbridging contact into said arc passage to establish an arc therein, anda tubular follower of insulating material movable into said are passagefor causing the arc to play in two series related branches one in eachof the annular spaces between said follower and said concentric tubes.

4. In a circuit interrupter, a pair of concentric tubes of insulatingmaterial defining an annular arc passage, a pair of stationary contactsdisposed adjacent one end of said pair of concentric tubes, a third tubeof insulating material movable between said stationary contacts intosaid arc passage, a movable contact carried by said third tube normallybridging said stationary contacts when said third tube is outside saidare passage, and means for moving said third tube into said are passageto cause said movable contact to draw an arc with each of saidstationary contacts.

5. Ina circuit interrupter, means of insulating material defining anannular arc passage open at one end and closed at the other end,separable contact means adjacent the open end of said arc passage, atubular member of insulating material open at one end and closed at theother end, said tubular member being normally disposed with its open ndadjacent to the open end of said are passage and in alignment with saidpasnals.

asvaviv sngaineans ior actuating said separable contact means toestablish an arc across the open end oi said are passage, and means iormoving said tubular member into the arc passag to confine the arebetween the walls of said tubular mom contacts into engagement with saidmovable con-= tact member and the other oi said spaced con= tacts toprovide a low resistance connection between said contacts and saidcontact member.

'7; a circuit interrupter, means of insulating mate ial defining anannular arc passage, a pair oi generally annular and concentricallydisposed,

spaced contacts adjacent one end of said are passage, a tubular memberof insulating material movable between said spaced contacts into said.

are passage, and a tubular contact carried by one end of said tubularmember and normally adapted to interconnect said spaced contacts,

each of said spaced contacts having an annular groove intermediate itsends for confining arcing between said spaced contacts and said tubularcontact to a portion of the contact surface on one side of said groove.

8. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least on of said terminals,said bridging means including means of insulating material defining anannular arc passage, separable contact means adjacent one end of saidare passage movable to open and closed circuit positions forinterrupting and establishing a circuit between said terminals whilesaid bridging means is in engagement with said terminals, a tubularmember of insulating material movable into said are passage upon sop- Ftricallv connecting said terminals and movable into and out ofengagement with at least one oi said terminals, said bridging meansincluding means of insulating material defining an annu= lar arcpassagebeparable contact means edja= cent one end of said are passagemovable to open and closed circuit positions for interrupting andestablishing a circuit between said terminals while said bridging meansis in engagement with said terminals, spring means, a tubular member ofinsulating material movable into said are passage by said spring meansto cause separation of said contact means, latch means normally holdingsaid tubular member against the bias oi said spring means, and operatingmeans operabl in one continuous movement for first releasing said latchmeans to cause said spring means to move said tubular member and contactmeans to the open circuit position and for thereafter mov hi saidbridging means out of engagement with at least on of said terminals. V

lhln a circuit interrupting device, a pair of spaced terminals, bridgingmeans normally elec,

iii

tricallv connecting said terminals and movable into and out oiengagement with at least one of said terminals, said bridging meansincluding means of insulating material defining an anion oration of saidcontact means, and operating means operable in one continuous movementfor first separating said contacts to establish an arc and to cause saidtubular member to be moved "into said are passage to extinguish the arcand.

for thereafter moving said bridging means out of engagement with atleast one of said termi= 9. In a circuit interrupting device, a pair ofspaced terminals, bridging means normally electrically connecting saidterminals and movable into and out of engagement with at least one ofsaid terminals, said bridging means including means of insulatingmaterial'defining an annular arc passage, having astationary contactadjacent one end thereof, a coacting contact movable into said arcpassage for establishing an arc therein while said bridging means is inengagerlment with said terminals, a tubular follower of insulatingmaterial movable into said arc passage to assist f are extinction, andoperating means operable in one continuous movement for first causingsaid movable contact and said follower to be moved into said are passageand thereafter for moving said bridging means out of ngagement with atleast one of said terminals.v

lar arc passage, separable contact means adja cent one end of said arepassage movable to open and closed circuit positions for interruptingand establishing a circuit between said terminals while said bridgingmeans is in engagement with said terminals, spring means biasing saidcontact means to the open circuit position, latch means normally holdingsaid contact means in the closed position against the bias of saidspring means, a tubular member of insulating material movable into saidare passage by said spring means upon separation of said contact means,and operating means operable in one continuous movement for firstreleasing said latch means to cause said spring means to move saidcontact means and said follower to the open circuit position and forthereafter moving said bridging means out of engagement with at leastone of said terminals, and means operable in response to movement ofsaid bridging means for moving said separable contact means and saidfollower to the closed circuit position.

12. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least one of said terminals,said bridging means including separable contact means, spring means foractuating said contact means to the open circuit means out of engagementwith at least one of i said terminals.

13. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electries-11y connecting said terminals andmovable into and out of engagement with at least one of said terminals,said bridging means including separable contact means, spring means foractuat ng said contact means to the open circuit position, latch meansrestraining the action of said spring means, and operating meansoperable in one continuous movement for first releasing said latchmeansto cause said spring means to move saidcontact means to theopen'circuit position and for thereafter moving said bridging means utof engagement with at least one of said ter inals, and means operable inresponse to movement of said bridging means for moving said separablecontact means to the closed circult position.

'14. In a circuit interrupting device, a pair of spaced terminals,bridging-means normally electrically connecting said terminals andmovable into and out of engagement with at least one of said terminals,said one terminal having limited movement with said bridging meansduring the initial movement of said bridging means towards the opencircuit position, said bridging means including separable contact means,spring means biasing said contact means to the open circuit position,latch means holding said contact means in the closed position againstthe bias or said spring means, operating means for operating saidbridging means out of engagement with at least said one terminal, andmeans actuated by said operating means during the limited movement saidwoone terminal with said bridging means tor releasing said latch means tocause said spring means to move said contact means to the open circuitposition. A

15. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least on of I ,saidterminals, said one terminal having limited movement with said bridgingmeans during the initial movement of said bridging means towards theopen circuit position, said bridging means including separable contactmeans, spring means ducting member on each end thereof adapted to engagesaid spaced terminals, said bridging member being movable into and outof engagement with at least one of said terminals, conbiasing saidcontact means to the open circuit position, latch means holding saidcontact means in the closed position against the bias of said springmeans, operating means for operating said bridging means out ofengagement with at least said one terminal, and means actuated by i saidoperating means during the limited movement of said one terminal withsaid bridging means for releasing said latch-means to cause said springmeans to move said contact means to the open circuit position, and meansoperable in response to movement of said bridging means followingdisengagement or the latter from said one terminal for relatching saidcontact means in the closed circuit position.

16. In a circuit interrupter, a pair of spaced terminals, a hollowbridging member at least partialiy of insulating material and having aconducting member on each end thereof adapted to engage said spacedterminals, said bridging member being movable into and out of engagementwith at least one of said terminals, conductingmeans within saidbridging member electrically connecting said conducting members, saidconducting means including separable contact means, means biasing saidcontact means to the open circuit position, latch means for normallyholding said contact means in the closed circuit position against theaction 0! said biasing means, and operating means operable in onecontinuous movement for first tripping said latch means to causeseparation of said contact means ducting means within said bridgingmember electrically connecting said conducting members, said conductingmeans including separable contact means, means biasing said contactmeans to the open circuit position, latch means for normally holdingsaid contact means in the closed circuit position against the action ofsaid biasing means, and operating means operable in one continuousmovement for first tripping said latch means to cause separation of saidcontact means to draw an are within said hollow bridging member and forthereafter moving said bridging member out of engagement with at leastone of said terminals, and means operable in response to movement ofsaid bridging memher out of engagement with said one terminal forrelatchlng said separable contact means in the closed circuit, position.

18. In a circuit interrupter, a pair of spaced terminals, bridging meansincluding a casing movably mounted on one of said terminals, a hollowblade member at least partially of insulating material extending fromsaid casing, a conducting member carried by the free end of said blademember adapted to be moved into and out of engagement with the otherterminal in accordance with movement of said casing, conducting meansincluding separable contact means within said bridging means connectingsaid conducting member andsaid casing, a spring biased actuating memberextending into said casing for moving said contact means to the opencircuit position, latch means for said actuating member to hold saidseparable contact means in the closed circuit position, operating meansfor said casing operable to move said blade member out of engagementwith said other terminal, and actuating means within said casingoperable during the initial movement of said casing to trip said latchmeans to cause said actuating member to move said contact means to theopen circuit position.

19. In a circuit interrupter, a pair of spaced terminals; bridging meansincluding a casing movably mountedon one of said terminals, a hollowblade member at least partially of insulating material extending fromsaid casing, a conducting member carried by the free end oi said blademember adapted to be moved into and out of engagement with the otherterminal in accordancewlth movement of said casing, conducting meansincluding separable contact means within said bridging means connectingsaid conducting member and said casing, a spring biased actuating memberextending into said casing for moving said contact means to the opencircuit position, latch means for said actuating member to hold saidseparable contact means in the closed circuit position, operating meansfor said casing operable to move said blade member out of engagementwith said other terminal, and actuating means within said casing ioperable during the initial movement of said casto draw an are withinsaid hollow bridging memtially of insulating material and having aconing to trip said latch means to cause said actuating member to movesaid contact means to the open circuit position, and means within saidcasing operative upon further movement of said casing for moving saidactuating member to its latched position.

20. In a circuit interrupter, a terminal, a hollow blade member at leastpartially of insulat- I ing material mounted for swinging movement,

a contact, an off-set support for pivotally mounting said contact onsaid terminal, a contact member on the free end of said blade memberadapted to be moved into and out-of engagement with saidpivotallysupported contact, said support being arranged to provide alimited amount of movement of said pivotally mounted contact with saidblade member during the initial movement of said blade member to theopen circuit position, separable contacts within said hollow blademember biased to the open circuit position but normally latched in theclosed circuit position to complete the electric circuit to saidterminal when said blade member is in the closed circuit position,operating means for swinging said blade member to the open circuitposition, and means operative in response to the initial movement ofsaid blade member to the open circuit position for separating saidseparable contacts to interrupt the circuit.

21. In a circuit interrupter, a pair of spaced terminals, a hollow blademember mounted for swinging movement to open and closed positions on oneof said terminals, said blade member having a yielding contact portionadjacent to the free end thereof, a contact member movably mounted onthe other terminal for receiving said yielding contact portion when saidblade member is in the closed position, a movable contact within saidhollow blade member adapted to coact with said yielding contact portionto establish a circuit between said terminals when said blade member isin the closed position, and support means for said contact member havinglimited relative movement with respect to said other terminal and saidblade member operative to cause a high pressure engagement between saidcontact member, said yielding contact portion and said movable contactwhen said blade member is moved to the closed circuit position.

22. In a circuit interrupter, a pairof spaced terminals, a hollow blademember mounted for swinging movement to open and closed positions on oneof said terminals, said blade member having a yielding wedge shapedcontact portion adjacent the free end thereof, a contact yoke adapted tocoact with said contact portion on.

said blade member, a support for movably mounting said contact yoke onthe other terminal, a movable contact within said hollow blade memberadapted to coact with said yieldingv contact portion to complete thecircuit between said terminals when said blade member is in the closedcircuit position, and operating means for swinging said blade member toopen and closed positions, said support providing lim.- ited swingingmovement of said contact yoke with said blade member and limitedrelative movement longitudinally of said blade member during the finalclosingmovement of said blade.

one of said terminals for swinging movement into ing to actuate saidcontacts to the open circuit position to establish an arc, means whollywithin said casing for extinguishing said arc, and operating meansoperable in one continuous movement for first releasing said actuatingmeans to separate said contacts, and for thereafter moving said casingout of engagement with respect to said other of said terminals.

24. In a circuit interrupting device, a pair 01' spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least one of said terminals,means latching said bridging means to said one terminal to normally holdsaid bridging means in the closed circuit position, sepable contactscarried by said bridging means biased to open circuit position, meansfor latching said separable contacts in the closed circuit position, andoperating means operable for first unlatching said separable contactlatching means and then unlatching said bridging means from said oneterminal to permit the bridging means to be moved out of engagement withsaid one terminal. Z5

mounted on one of said terminals for swinging movement into and out ofengagement with the other of said terminals, an engageable latching.lever pivotally mounted adjacent the free end of said bridging memberfor normally holding said bridging member in the closed circuitposition, separable contacts within said bridging member biased to theopen circuit position, means for latching said separable contacts in theclosed circuit position, and means actuated by movement of said latchinglever torelease said separable contact latching means to cause saidcontacts to interrupt the circuit prior to movement of said bridgingmeans out of engagement with said other terminal.

26. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least one of said terminals,means latching said bridging means to said one terminal to normally holdsaid bridging means in the closed circuit position, separable contactscarried by said bridging means biased to open circuit position, meansfor latching said separable contacts in the closed circuit position, andoperating means operable for first unlatching said separable contactlatching means and then unlatching said bridging means from said oneterminal to permit the bridging means to be moved out of engagement withsaid one terminal, and means operable in response to movement of saidbridging means to the'open position for latching said separabl contactsin the closed circuit position.

2'7. In a circuit interrupter, a pair of spaced terminals, a hollowbridging member pivotally mounted on one of said terminals for swingingmovement into and out of engagement with the other of said terminals, anengageable latching lever pivotally mounted adjacent the free end ofsaid bridging member for normally holding said bridging member in theclosed circuit position, separable contacts within said bridging memberbiased to the open circuit position, means for latching said separablecontacts in the closed circuit position, and means actuated by movementof said latching lever to release said separable contact latching meansto cause said contacts to interrupt the circuit prior to mo'vementoisaid bridging means out of engagement with said other terminal. andmeans activated by movement 01' said bridging member to the open circuitposition relatching said separable contacts in the closed circuitposition.

28. A switching device comprising a pair of spaced insulators, aterminal supported on each of said insulators, bridging means includingfusible means pivotally mounted on one of said terminals for swingingmovement into and out of engagement with said other terminal for makingand breaking the electrical circuit between said terminals, a thirdterminal insulatingly supported in spaced relation with said pair ofterminals, and circuit interrupting means including a pair of separablecontacts disposed between said third terminal and one of said pair ofterminals, means for separating said contacts while said circuitinterrupting means is in engagement with its respective terminals, saidone oi! said pair oi terminals serving as a common support for saidfusible means and said circuit interrupting means. V 29. Circuitinterrupting means comprising three spaced conducting terminals, acircuit interrupting device movably supported between two of saidterminals, said circuit interrupting device being adapted to interruptoverload currents while in engagement with said two terminals and beingmovable out of engagement with at least one of said terminals to insertan air gap of appreciable length in the circuit, and a second circuitinterrupting device connected in series with said first circuitinterrupting device and supported between two of said terminals one ofwhich is common to both interrupting devices, said second interruptingdevice having separable contacts adapted to interrupt load currents oflesser magnitude than the overload current interrupted by said firstcircuit interrupting device, and means for separating said contactswhile said second circuit interrupting means is in engagement with itsrespective terminals.

30. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having a casing supported for limitedrelative movement with respect to said terminal member, said casinghaving an external contact terminal engageable by said blade means atleast during the initial open-- ing movement thereof, separable contactswithin said casing connected for establishing a circuit through saidcasing from said terminal member to said blade means, means foractuating said blade means to open circuit position, said separablecontacts being movable with said casing for maintaining the circuittherethrough until said blade means has ben moved out of engagement withsaid terminal member, and means responsive to further movement of saidcasing 'by said blade means to cause said separable ontacts to open andinterrupt the circuit.

31. The combination with a switch having a terminal member and blademeans operable into and out oi engagement with said terminal member ofan arc extinguishing device having a casing supported for limitedrelative movement with respect to said terminal member, an electricalcircuit through said casing including separable contacts at least one ofwhich is connected to said terminal member, means for releasablyconnecting said blade means with another of said separable contacts toestablish a circuit in parallel with the gap formed between saidterminal member and said blade means, said connecting means includingmeans for moving said casing relative to said terminal member, and meansresponsive to predetermined movement oi said casing followingdisengagement of said blade means from said terminal member to causesaid contacts to separate and interrupt the circuit.

'32. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having a casing supported for limitedrelative movement with respect to said terminal member, an electricalcircuit through said casing including separable contacts at least one ofwhich is connected to said terminal member, means for releasablyconnecting said blade means with another of said separable contacts toestablish a ircuit in parallel with the gap formed between said terminalmember and saidblade means, said connecting means including means formoving said casing relative to said terminal member, means biasing saidseparable contacts to the open circuit position, latch means fornormally holding said separable contacts in the closed position, andmeans responsive to a predetermined movement of said casing for trippingsaid latch means to cause said contacts to separate with a quick action.

33. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member oian arc extinguishingdevice having a casing, a circuit through saidcasing including separable contacts at least one of which is connectedto said terminal member, means for releasably connecting said blademeans with another of said separable contacts to establish a circuit inparallel with the gap formed between said terminal member and said blademeans, means biasing said separable contacts to the open circuitposition, means normally holding said contacts in the closed position,an operating member disposed for relative movement with respect to saidcasing for controlling said holding means, said connecting meansincluding means operative to produce relative movement between saidoperating member and said casing at least following disengagement oisaid blade means from said terminal member to cause said holding meansto release said separable contacts only following disengagement of saidblade means from said terminal members.

34. In a circuit interrupter, arc extinguishing means includingseparable contacts normally held in the closed circuit position, meansof insulating material movable to a position between said contacts,biasing means for actuating said contacts to the open circuit positionand said insulating means to said position between said contacts,operating means for moving said separable contacts and insulating meanswith respect to said biasing means to increase the operating force ofsaid biasing means, and means responsive to a predetermined movement 01said separable contacts for releasing said separable contacts andinsulating means for movement of said contacts to the open circuitposition and of said insulating means to a position therebetween.

35. In a circuit interrupter, a support, a casing mounted thereon andhaving limited relative movement therewith, separabl contacts in saidcasing, resilient means in said casing andconnecting said casing and atleast one of said contacts-whereby relative movement 01' said casing inone direction will stress said resilient means in a direction to movesaidcontacts to the open circuit position, latch means in said casingfor normally holdingsaid separable contacts in the closed position, andmeans responsiv to a predetermined relative movement of said casing fortripping said latch means to cause said biasing means to quickly opensaid contacts. I

36. In a circuit interrupter, a support, a cas-.

ing mounted thereon and having limited rela- 3'7. In a circuitinterrupter, a. support, a casing mounted thereon and having limitedrelative movement therewith, separable'contacts within said casingarranged for movement therewith at least during a portion of themovement or said casing, latch means tor holding said contacts in theclosed circuit position, operating mean for moving said casing withrespect to said support, at least one of said contacts having relativemovement with respect to said casing and another of said contactsfollowing release of said latch means, means responsive to predeterminedmovement of said casing for releasing said latch means, and biasingmeans operative to move said one contact with respect to another of saidcontacts following release of said latch means.

38. In a circuit interrupter, a pair of separable disconnectingcontacts, arc extinguishing means having separable arc establishingcontact means. biasing means for actuating said arc establishingcontacts means to open circuit position, latch means for restraining theaction oi said biasing means, and a movable operating member operativeupon continuous movement in one direction for initially releasing saidlatch means to cause the circuit to be opened at said arc establishingcontact means and'for subsequently causing said pair of disconnectingcontacts to separate to insert an isolating break in the circuit.

39. In a circuit interrupter, a pair of separable disconnectingcontacts, arc extinguishing means having separable arc establishingcontact means, biasing means for actuating. said arc establishingcontact means to open circuit position, latch I means for restrainingthe action oi. said biasingmeans, a movable operating member operativeupon continuous movement thereof in one direction for initiallyreleasing said latch means to cause the circuit to be opened at said areestablishing contact means and for subsequently causing said pair ofdisconnecting contacts to separate to insert an isolating break in thecircuit, said operating member upon movement in the opposite directioncausing said biasing means said terminals, said bridging means includingseparable contact means, spring means biasing said contact means to theopen circuit position; latch means holding said contact means in theclosed position against the bias of said spring means, and operatingmeans operable-in one continuous movement for first releasing said latchmeans to cause said spring means to move said contact means to the opencircuit position and for thereafter moving said bridging means out ofengagement with at least one of said terminals.

41. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least one 0! said terminals,said bridging means including separable contact means, spring meansbiasing said contact means to the open circuit position, latch meansholding said contact means'in the closed position against the bias ofsaid spring means, and operating means operable in one continuousmovement for first releasing said latch means to cause said spring meansto move said contact means to the open circuit position andfor'thereatter moving said bridging means out of engagement with atleast one of said terminals, and means operable in response tomovement'of said bridging means for moving said separable contact meansto the closed circuit position. v 1 l 42. In a circuit interruptingdevice, a pair of spaced terminals, bridging means normally electricallyconnecting said terminals and movable into and out of engagement with atleast one 01' said terminals, said one terminal having limited relativemovement with respect to said bridging means. without breaking contactduring the initial opening movement 01 said bridging means, saidbridging means including separable con tact means, spring meansoperating said contact means to open circuit position, latch means forrestraining the action of said spring means, operating means for movingsaid bridging means out of engagement with at least said one terminal,and means actuated by said operating means during the limited relativemovement between said one terminal and said bridging means for releasingsaid latch means to cause said spring means to move said contact meansto the open circuit position.

43. In a circuit interrupter, a pair of concentric tubes of insulatingmaterial defining an annular arc passage, separable contact means fordrawing an are adjacent one end of said are passage, and a third tube ofinsulating material relatively movable between said pair of concentrictubes for causing said are to be restricted in cross-section andlengthened along a path substantially twice the length of the relativemovement between said last-named tube and said pair of concentric tubes,and operating means extending through at least one oi-said pair ofconcentric tubes.

for actuating said are establishing contact means to be relatched in theclosed circuit position and movement of said pair of disconnectingcontacts to the closed circuit position.

40. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrically connecting said terminals andmovable into and out of engagement with at least one or 44. In a circuitinterrupting device, a pair of spaced terminals, bridging mean normallyelectrically connecting said terminals and movable into and out 01'engagement with at least one of said terminals, said-one terminal havinglimited movement with said bridging means during the initial movement ofsaid bridging means towards the open circuit position, said bridgingmeans including separable, contact means, operating means for operatingsaid bridging means out of engagement with at least said one terminal,and

means actuated by said operating means during the limited movement ofsaid one terminal with said bridging means for moving said contact meansto their open circuit position.

45. In a circuit interrupting device, a pair of spaced terminals,bridging means normally electrlcally connecting said terminals andmovable into and out of engagement with at least one 01' said terminals,said one terminal having limited movement with said bridging meansduring the initial movement or said bridging means towards the opencircuit position, said bridging means including separable contact means,operating means for operating said bridging means out of engagement withat least said one terminal, means actuated by said operating meansduring the limited movement of said one terminal with said bridgingmeans for moving said contact means to their open circuit position, andmeans operable in response to movement of said bridging means followingdisengagement oi the latter from said one terminal tor reclosing saidcontact means.

46. Circuit interrupting means including three spaced terminals,insulating means supporting said terminals, a pair of circuitinterrupting devices supported on said terminals, each of said devicesconnecting a pair 01 said terminals with one terminal common to bothdevices, one said devices being movably mounted on one of its associatedterminals for movement into and out of engagement with the other of itsterminals, and the other of said devices being connected to said commonterminal between its insulating support and the other of said devices.

47. Circuit interrupting means including three insulated spacedterminals, a pair of circuit interrupting devices supported on saidterminals, each of said devices connecting a pair of said terminals withone terminal common to both devices, one of said devices comprising anexpulsion type interrupting device and having the end thereof which isopen upon the occurrence of an interrupting operation mounted on saidcommon terminal outwardly of the other or said devices so as to bedirected angularly away from. said other device, to direct the productsor ex pulsion angularly away from said other device.

48. In a circuit interrupter, a pair or concentric tubes of insulatingmaterial defining an annular arc passage, separable contact means fordrawing an are adjacent one end of said are passage, and a third tube ofinsulating material relatively movable between said pair of concen trictubes for causing said arc to be restricted in cross-section andlengthened along a path substantially twice the length of the relativemovement between said last-named tube and said pair of concentric tubes,and means extending through the inner one of said concentric tubes andconnected to said contact means.

49. In a circuit interrupter, a blade member mounted for movement intoand out of engagem'ent with respect to a cooperating contact member,said contact member being mounted for limited movement with said blademember but angularly thereto adjacent the closed position of saidmembers, one oi said members adapted to receive the other, and at leastone of said members having a tapered engaging portion adapted to bemoved into and out 01' high pressure engagement with the other of saidmembers during said movement or said members together,

50. In a circuit interrupter, a blade member mounted for movement intoand out of engagement with respect to a cooperating contact memlimitedmovement with said blade member but angularly thereto adjacent theclosed position of said members, said blade member having a wedge-shapedcontact portion for engaging a' yoke portion on said contact member sothat said portions are movable into and out of high pressure engagementwith the other of said members during said movement of said memberstogether.

51. In a circuit interrupter, arc-extinguishing means includingseparable contacts normally held in a closed circuit position, means ofinsulating material movable to a position between said contacts, biasingmeans for actuating said contacts to the open circuit position and saidinsulating means to said position between said contacts, operating meansfor stressing said biasing means, and means responsive to apredetermined movement of said operating means for releasing saidseparable contacts and insulating means for movement of said contacts tothe open circuit position and or said insulating means to a positiontherebetween.

52. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having 9. casing, a circuit through saidcasing including separable contacts at least one of which is connectedto said terminal member, means for releasably connecting said blademeans with another 01' said separable contacts to establish a circuit inparallel with the gap formed between said ter-' minal member and saidblade means, means Ior biasing said separable contacts to the opencircuit position, and means responsive to movement of said blade meansfor controlling said biasing means to separate said separable contactsto quickly open the circuit after said blade means has moved out ofengagement with said terminal member, and prior to release or said blademeans from the contact with which it is associated.

53. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having a casing, a circuit through saidcasing including separable contacts at least one of which is connectedto said terminal member, means for releasably connecting said blademeans with another oi said separable contacts to establish a circuit inparaliel with the gap formed between said terminal member and said blademeans, means for biasing said separable contacts to the open circuitposition, and means responsive to movement of said blade. means forcontrolling said biasing means to separate said separable contacts toquickly open the circuit after said blade means has moved out ofengagement with said terminal member, and prior to release of said blademeans from the contact with which it is associated, and said blade meansupon movement thereof in a reverse direction toward said terminal memberadapted to first releasably engage said other contact 01' said arcextinguishing device, and said controlling means being responsive tosaid reverse movement of said blade means to thereafter cause engagementoi said contacts.

54, In a circuit interrupter, a pair of spaced terminals, a bridgingmember plvotally mounted on one of said terminals for swinging movementinto and out of engagement with the other 01 said terminals, anengageable latching lever pivotally mounted adjacent the free end ofsaid bridging member for normally holding said bridging member in theclosed circuit position, said lever being pivotally movable to latch andunlatch said bridging member in the closed circuit position, stop meanslimiting pivotal movement of said lever whereby a continuous pullexerted on said lever in one direction will first release said bridgingmember and thereafter cause pivotal movement thereof to an open circuitposition, separable contacts within said bridging member biased to theopen circuit position, means for latching said separable contacts in theclosed circuit position, and'means actuated by pivotal movement of saidlatching lever to release said separable contact latching means to causesaid contacts to interrupt the circuit prior to movement of saidbridging means out of engagement with said other terminal.

55. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having a casing mounted on said terminalmember. a circuit through said casing including separable contacts atleast one of which is connected to said terminal member, means forreleasably connecting said blade means with another of said separablecontacts to establish a circuit in parallel with the gap formed betweensaid terminal member and said blade means, means for biasing saidseparable contacts to the open circuit position, and means responsive tomovement of said blade means for controlling said biasing means toseparate said separable contacts to quickly open the circuit after saidblade means has moved out of engagement with said terminal member, andprior to release 01 said blade means from the contact with which it isassociated.

56. The combination with a switch having a terminal member and blademeans operable .into and out of engagement with said terminal member ofan arc extinguishing device having a casing, a circuit through saidcasing including separable contacts at least one of which is connectedto said terminal member, means for releasably connecting said blademeans with another of said separable contacts to establish a circuit inparallel with the gap formed between said terminal member and said blademeans, means for biasing said separable contacts to the open circuitposition, means responsive to movement of said blade means forcontrolling said biasing means to separate said separable contacts toquickly open the circuit after said blade means has moved out ofengagement with said terminal member prior to release oi said blademeans from the contact with which it is associated, and means operablecontinuously in one direction for moving said blade means to an opencircuit position at which it is spaced from said terminal member andsaid other of said separable contacts, whereby in a circuit interruptingoperation said blade mean is first separated from said terminal memberbut remains in engagement with said other or said separable contacts,thereafter said contacts are quickly separated to interrupt the circuit,and then said connection of said blade means and contact is released,and finally said blade means moves to the aforesaid open circuitposition.

57. The combination with a switch having a terminal member and blademeans operable into and out of engagement with said terminal member ofan arc extinguishing device having a casing, a circuit through saidcasing including separable contacts at least one 01 which is connectedto said terminal member, means for releasably connecting said blademeans with another 0! said separable contacts to establish a circuit inparallel with the gap formed between said terminal member and said blademeans, means for biasing said separable contacts to the open circuitposition, means responsive to movement of said blade means forcontrolling said biasing means to separate said separable contactstoquickly open the circuit after said blade means has moved out ofengagement with said terminal member prior to release of said blademeans from the contact with which it is associated, means operablecontinuously in one direction for moving said blade means to an opencircuit position at which it is spaced from said terminal member andsaid other oi! said separable contacts, whereby in a circuitinterrupting operation said blade means is first separated from saidterminal member but remains in engagement with said other of saidseparable contacts, thereafter said contacts are quickly separated tointerrupt the circuit, and then said connection of said blade means andcontact is released, and finally said blade means moves to the aforesaidopen circuit position, and said operating means upon reverse movementthereof adapted to move said blade means into engagement with saidterminal member, whereby in a circuit closing operation said blade meansis first moved into engagement with said other of said separablecontacts, and thereafter said controlling means being responsive toiurher movement of said blade means toward said terminal member to closesaid separable contacts.

LEON R. LUDWIG. JAMES H. FRAKES. MARTHA M. SCHOFIELD, Administratrix ofthe Estate of Stanley T. Schofleld, Deceased.

